Daily round the clock routine maintenance of both boiler Routine maintenance of HP LP Valves and safety valves and break down maintenance of Pressure Parts HP LP Valves and safety valves of Unit 8 and 9 DTPS Kasimpur

Amount

PART-A

Daily round the clock routine maintenance with respect to both boiler of Unit # 8 & 9 ‘D’ TPS

PART-B

Routine maintenance of HP/LP valves, Safety valves, PRDS valves in general shift.(Except Sundays and Holidays)

Part-C Attending the leakages of water wall tubes in boiler Furnace from down comer / ring header to 50 meter including burner Zone:

Attending tube leakage up to Ist ten H.P. weld joints. (irrespective of number H.P. weld joints in one frequency)

Attending tube leakages for each H.P. weld joints beyond 10Nos. of H.P. weld joint.

Attending the leakages from economizer / LTSH tube

Attending tube leakage up to Ist ten H.P. weld joints.(irrespective of number H.P. weld joints in one frequency

Attending tube leakages for each H.P. weld joints beyond 10Nos. of H.P. weld joint.

Attending the leakages in ceiling super heater tubes situated in furnace top before platen super heater, platen super heater tubes

Attending tube leakage up to Ist ten H.P. weld joints.(irrespective of number H.P. weld joints in one frequency).

Attending tube leakages for each H.P. weld joints beyond 10 Nos. of H.P. weld joint

Attending the leakages in cold reheat & HRH tubes, Arch Tubes, screen tubes, water wall hanger tubes, super heater hanger tubes, final super heater, exit super heater tubes, extended water wall tubes, ceiling super heater tubes beyond platen super heater

Attending tube leakage up to Ist ten H.P. weld joints (irrespective of number H.P. weld joints in one frequency)

Attending tube leakages for each H.P. weld joints beyond 10 Nos. of H.P. weld joint

Attending the leakages from SCW super heater tubes and extended super heater tubes

Attending tube leakage up to Ist ten H.P. weld joints (irrespective of number H.P. weld joints in one frequency)

Attending tube leakages for each H.P. weld joints beyond 10 Nos. of H.P. weld joint

Attending the leakages of hand hole plates of different pressure part header by removing hand hole plates with hand hole cutting equipment, re welding of the same after complete preparations and stress relieving of the same after welding if required. Rates should be quoted on as per jobs basis.

Attending the leakages of header stubs up to Ist ten stubs joints in one frequency of different pressure parts headers of boiler.

Fixing of sky climber in boiler furnace after making proper platform on bottom ash hopper, its operation during execution of the works and dismantling and removal of ash hopper platform after completion of jobs. Rates should be quoted on as per job basis

Removal of damaged clamps / binders /scallop bars etc. and replacement / refitting of the same with new / repaired one in different zones of the pressure parts. The rates should be quoted on as per No. basis as under.

‘U’ Clamps

Scallop bars

Binders, support band, lugs

Flexible Connectors (male / female)

Fabrication of Hot bends of various degrees and radius of curvature from straight pressure parts tubes by filling sand and heating gas to required temperature of following materials.

Carbon Steel

Alloy Steel

Stitch Welding of fines of water / steam cool wall for securing of respective positions of tubes.

Rectification / replacement of Ash Protector / Shielding / Cassette baffles found damaged / eroded / dislocated or providing new protector in the following pressure part zones ( Rates should be quoted on as per No. basis)

Tubular (half round) protector of platen super heater / Re heater inlet etc and their spacer tubes. Protector /shielding shall be rectified / installed with the help of sky climber

Rectification / replacement of box type protector / cassette baffles found damaged / eroded / dislocated in LTSH / Economizer etc.

Tubular protectors / shielding of water wall hanger tubes / water wall screen tubes / final super heater / LTSH / economizer / re heater etc. Protector / shielding shall be rectified / installed with the help of scaffolding to be erected by agency as per requirements.

Rectification / replacement of box type protector / cassette baffles found damaged / eroded / dislocated of water wall hanger tubes / water wall screen tubes / final super heater / re heater etc. Protector / shielding shall be rectified / installed with the help of scaffolding to be erected by agency as per requirements

Erection of Scaffolding and plate form in the following areas:-

Economizer hopper (above).

S-Panel & bottom ash hopper.

Reheater inlet & outlet.

Water wall screen tube / final super heater / super heater screen tube

Build up of eroded portion of the tubes caused by ash / steam erosion using suitable welding electrodes matching with parent metal composition. Depth of erosion up to 2.5mm, length of erosion up to 250 mm.

Lifting and taking out the complete coils in pair of LTSH horizontal coils (upper or lower ) after cutting clamps supports , clits, stoppers and releasing from subsequent headers and coil & their restoration after placement of coil.

Lifting and taking out the complete coils of Economizer (upper or lower) after cutting clamps supports , clits, stoppers and releasing from subsequent headers and coil & their restoration after placement of coil.

Replacement of eroded / damaged tubes / bends of pressure parts in different zones of boiler during preventive maintenance as per procedure mentioned in annexure of the following

Carbon / low alloy (T-11) joint

High alloy (T-22) joint

Stainless Steel Joint

Shifting of sky climber in boiler furnace at different locations for attending and inspection of various pressure part zones. Rates should be quoted on as per job basis

Cutting and removal of skin casing / high crown plate by grinder and welding the same with suitable electrode by High pressure welding method, after completion of repair jobs of pressure parts if any.

Thickness - up to 15 mm

Thickness - 16mm or above

Replacement of Safety Valve

Replacement of following size valves.

15mm to 25 mm valves.

40mm to 50mm valves.

65mm to 70mm valves

100mm valves

150mm to 200mm valves

Servicing of feed line gate / control valves / NRV size NB- 350 mm, NP-280 Kg./cm² valves covered are E-1, E-2, FD- 13, 14, 15, 16, 17, 18.

Servicing of low load line gate & control valves size NB-200mm NP-280Kg/ cm² valves covered are FD-19, 20, 21

Servicing of Pneumatically operated S/H, R/H Attemperation control valves & RH Spray block valves.

Servicing of main Isolating valve SD-1, SD-10 at the inlet of SH spray station, size: NB- 150mm, NP-280Kg / cm².

Servicing of main isolating valve of main steam line (L&R) M.S.-123 & M.S.-124, Nb-300mm, NP-280Kg/ cm².

Servicing bypass valves of main steam valves –MS-125, 126, 127, 128, Nb-50mm, NP-250Kg/ cm².

Servicing of bypass valves of feed station, low load line valve and main isolation valve of inlet to SH-Nb-25mm, NP-250Kg./ cm².

Servicing of boiler drum safety valves SLSV Type at 56 meter elevation of boiler. MAXIMUM WORKING PARAMETERS: - Pr.-182.5 Kg/cm², Temp. 357ºC (SV1),size-3"/6" Pr.-186.2 Kg./cm², Temp.357ºC (SV 2), size-3"/6" Pr.-188.0 Kg./cm², Temp.357ºC ( SV 3), size-3"/6"

Servicing of electromagnetic relief valve (implies safety valve). MAXIMUM WORKING PARAMETERS:- Pr.-164.6 Kg/cm², Temp.540ºC size-2.5"/4".

Servicing of safety valves installed on hot reheat and cold Reheat line at about 56meter elevation. MAXIMUM WORKING PARAMETERS:- i) CRH SV-8, Pr.-47Kg/ cm², Temp.-345 ºC, size-6"& 8". ii) HRH SV-9 & SV 10, Pr.43.8 Kg/ cm², Temp.-540 ºC, size-6"& 8". iii) HRH SV -11& SV 12, Pr.45.9 Kg/ cm², Temp.-540 ºC, size-6"& 8".

Servicing of safety valve on soot blower line at 56 mtr. elevation. MAXIMUM WORKING PARAMETERS:- SV -15, Pr.-40Kg / cm², Temp.-333 ºC, size-1.5"/2.5"

Servicing of high-pressure valve’s & NRV’s at different elevation boiler from ‘0’meter level to 56 meter level nominal bore may vary from Ø 10mm to Ø100mm.

Servicing / replacement of Pneumatic / manual valves of oil station at AB /CD/ EF Elevation.

Servicing / replacement of oil line valves and NRV’s of oil station at AB / CD /EF elevation of boiler.

Servicing of pneumatic operated NB 150mm / 300 mm valves on Aux. PRDS line.

Servicing of electrically drive steam valve NB 100mm to 300mm on Aux. PRDS line.

Servicing of electrically drive Nb- 50mm valves on Aux. PRDS line

Servicing of pneumatic operated control valve size NB 50 to 100 mm at different floors of boiler from ‘0’meter level to 56 meter level.

Servicing of hand operated valve/NRV of size NB 150 to 250mm at different floors of boiler from‘0’meter level to 56meter level.

Servicing of hand operated valves /NRV’s of size Nb 300 to 350mm at different floors of boiler from‘0’meter level to 56 meter level. The

Servicing and revisioning of steam valves & NRV’s of Aux. PRDS line. Rate to be quoted per mm basis.

Changing flange gaskets of valve’s & flange at different floors from ‘0’meter level to 56 meter level of boiler and at PRDS floor. Rate should be quoted on per mm basis.

Replacement of gland packing with new one from valves leaking from glands. Rate should be quoted on per mm basis.

Attending leakages of pipeline & headers etc. of main boiler, and aux. PRDS of 250 MW by cutting grinding and H.P. welding of damaged portion putting new spools/bends if required.

Servicing of safety valve of Aux. PRDS size NB 150-200mm.

Replacement of Pipe dia. 10 mm to 40mm.

Attending minor leakage from pipe, bend etc at different place of boiler side ‘0’ meter to ‘54’ meter.

Replacement of gasket of Manhole of Boiler drum

Syndicate Engineers